Embodiments of the inventive concept described herein relate to a sludge drying apparatus, and more particularly to a sludge drying apparatus that may improve an efficiency of drying sludge that is sewage deposit residues and simplify a drying process.
A oceanic discharge reference for wastes including sewage sludge has been significantly reinforced as'96 protocol of London Agreement came into effect, and Korean government revised Enforcement Degree for Ocean Environment Management Law (on Feb., 2006), and established a sewage sludge comprehensive measure in 2008 based on ‘Sewage sludge management comprehensive measure’ established on May 2007, and has pushed ahead construction of sewage sludge resourcing facilities for discharge of 0% to the ocean, investigation of sludge, distribution of the sewage sludge management technology, and revision of the sewage sludge related rules.
Further, a management guide for installation of sewage sludge treatment facilities was shaped up in 2011 to determine the purpose and range for management of facilities, and environmental problems due to sewage sludge are being positively coped with as the guides for support, installation, and management of government subsidies have been made clear.
In response, as of May, 2012, 43.3% of the sewage sludge except for decomposition, incineration, and solidification is dried, and 98.6% of the sewage sludge except of drying, powdering, and burial is utilized as a dried fuel.
Here, a drying process has to be accompanied first to dry sewage sludge containing moisture of 70 to 80% or more, and the sewage sludge drying method for this includes a direct drying method of directly heating sludge or bringing sludge into contact with hot wind (LNG, 400 to 800° C.) and an indirect drying method of using vapor (200° C.) or hot oil, and currently, a flash drier using hot wind, a rotary drier, and a multiple hearth furnace are generally used.
However, because most of the driers using hot wind dry moisture of a heating target (sewage sludge) through radiation, conduction, or convection of heat from a surface of the heating target to the interior of the sludge, much drying time is consumed and the sizes of the apparatuses are large.